How to Protect the Pipelines From Corrosion

The pipelines should be protected against the corrosion development for longer service life. To do this, there are special stray current drainage protection stations (DBZ)

Drainage Types

Presently, there are several types of drainage:

• polarized;
• direct;
• ground;
• intensified.

Stray currents are directed either to the soil or to the source. Soil method presupposes the pipeline grounding. This can be done with additional electrodes in anode zones. For direct drainage one end of the electric wires is connected with the rails of the railway road in an electrified mode, while the other end of the electric wires is connected with the pipeline. In this case the railway network is a negative pole of stray current source. Polarized method has unidirectional conductivity only. It is disabled in automatic mode when the potential on the rails is positive. A drainage current can be increased with a converter which can be additionally included in a circuit. This diagram can be used in an intensified drainage.

Advantages of Drainage Protection

The main advantage of these units is their simplicity and a lack of current source which is rail - pipeline potential difference caused by the movement of the electric locomotives combined with stray currents. Reverse-fed circuit-breakers or traditional electric fuses can play the role of a protective device. The circuit-breakers are more preferable as they recover the drainage circuit after a drop in current, which is dangerous for a station. DBZ is vandal-proof, including non-authorized access to the equipment. No rodents, insects, reptiles, precipitations can get inside the equipment. The stations are popular in energy, oil, gas, chemistry industries, in utility area, in industrial sites. They are reliable, easy to deal with and have a long service life.

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